S32K3 LPSPI pcs question

focusdoit — Sun, 17 May 2026 22:49:46 GMT

Hi Nxp experts:

If I manually control the LPSPI Chip Select (CS) using a GPIO pin, will the SpiCsPolarity setting in the S32DS configuration tool still affect it? Do I need to disable the PCS (Peripheral Chip Select) selection in the tool? Also, what is the purpose of the SpiHostRequest parameter?

Re: S32K3 LPSPI pcs question

VaneB — Mon, 18 May 2026 18:04:35 GMT

Hi @focusdoit

If I manually control the LPSPI Chip Select (CS) using a GPIO pin, will the SpiCsPolarity setting in the S32DS configuration tool still affect it?

No, it should not affect the behavior.

If you are using a GPIO as the Chip Select, you are responsible for controlling it.. The SpiCsPolarity parameter applies to hardware-controlled CS managed by the LPSPI peripheral, not to GPIO-controlled signals.

Do I need to disable the PCS (Peripheral Chip Select) selection in the tool?

If you are working with low-level drivers (IP) in ConfigTools, you only need to configure the desired pin as a GPIO, and you should not configure any PCS pin.

For high-level drivers (MCAL), in addition to configuring the pin as GPIO, there is a parameter called SpiCsSelection. This parameter should be set to CS_VIA_GPIO. In this case, the driver will use notifications (defined by the nodes SpiJobStartNotification and SpiJobEndNotification) to control the CS pin via GPIO for each SPI job.

Also, what is the purpose of the SpiHostRequest parameter?

In Master mode, this parameter allows the LPSPI module to start a new SPI transfer only when the host request input is asserted. If the LPSPI is busy, the host request input is ignored.

In Slave mode, it causes the HREQ output pin to assert when data is available to be transmitted.

BR, VaneB

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S32K3 LPSPI pcs question

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